Refrigerating apparatus having means for preventing condensation



March 24, 1953 J. R. FEHR REFRIGERATING APPARATUS HAVING MEANS FOR PREVENTING CONDENSATION Filed March 5, 1951 INVENTOR. Jim. R. Hm: BY

Patented Mar. 24, 1953 REFRIGERATING APPARATUS HAVING MEANS FQR PREVENTING CONDENSA- TION John R. Fehr, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application March 3, 1951, Serial No. 213,783

8 Claims.

This invention relates to refrigeration and particularly to refrigerated cabinets having refrigcratin apparatus installed therein.

Complicated and expensive insulated molding members have been employed in refrigerator cabinet structures to break the metal-to-metal contact between the liner of a compartment within the cabinet and the metal exterior walls thereof adjacent to the compartment access opening normally closed by a door. In spite of the complicated and expensive molding members and elaborate sealing or insulating means heretofore employed about the access opening of refrigerator cabinets entirely satisfactory results have not always been obtained. The low temperature maintained within a refrigerated food storage compartment of a refrigerator cabinet leaks past, or is transmitted beyond the seal on the door which closes an access opening, thus causing condensation and accumulation of moisture on these exposed surfaces of the cabinet. Under certain conditions this moisture may accumulate in sufficient quantity to flow from the surfaces upon which it accumulates onto the floor, but may also cause discoloration and deterioration of the cabinet exterior finish.

An object of my invention is to provide iproved means for preventing condensation or accumulation of moisture on the exterior wall surface of a refrigerator cabinet and particularly along a door which closes an access opening leading to the interior of a compartment in the cabinet.

Another object of my invention is to provide means whereby heat generated by an element employed to illuminate the interior of a food storage compartment of a refrigerator cabinet is utilized to warm that portion of the exterior wall surface of the cabinet adjacent the door opening therein, and particularly the mullion or that portion of the exterior wall surface which lies between the doors of adjacent refrigerated compartments.

A further object of my invention is to render the combined illuminating and heating means effective automatically by movement of one of the compartment doors and/ or by operation of an element of the refrigerating system associated with the cabinet.

Further advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a view of a refrigerating apparatus showing the front of a refrigerator cabinet having the present invention embodied therein; 7

Fig. 2 is an enlarged vertical sectional view of the refrigerating apparatus shown in Fig. 1 taken on the line 22 thereof;

Fig. 3 is an enlarged fragmentary sectional view taken on the line 3-3 of Fig. 2, showing illuminating means for one of the compartments of the refrigerator cabinet;

Fig. 4 is an enlarged fragmentary sectional view taken on the line 4-4 of Fig. 3, showing another view of the illuminating means; and Fig. 5 is a diagrammatic view showing a refrigerating system of the type installed in the refrigerator cabinet of Fig. 2, together with the electrical'control circuit associated therewith.

Referring to the drawings illustrating my invention, I have shown in Fig. 1 thereof a refrigerating apparatus including a household refrigerator cabinet having a closed refrigerating system associated therewith. The refrigerator cabinet, generally represented by the reference character It, includes a plurality of exterior metal walls or panels H and a plurality of metal liners l2 and I3 (see Fig. 2) forming walls of an upper food storage compartment Hi and a lower food storage compartment i5 respectively. Insulating material it is interposed between the walls H and liners l2 and I3 to effectively insulate the compartments I4 and it from one another and from' the exterior of the cabinet. Each of the compartments M and I5 is provided with an access opening in the front wall of cabinet It. A door ll normally closes compartment I4, while a door l8 normally closes compartment l5. The exterior metal walls or panels H extend downwardly beyond the insulated bottom wall of compart-merit it to provide a machine compartment H9 in the lowermost part of cabinet Ill, which compartment is normally closed by door 29. That portion of the exterior cabinet wall II at the front of cabinet It and located in front of the insulated wall is between the liners l2 and 13 forms a mullion 2| extending horizontally across the cabinet between compartments I l and I5. lT'he mullion 2i cooperates with other front wall surfaces H of cabinet Ill to form abearing-surface for gaskets carried by the doors H and I8 in order to seal the access openings of the food storage compartments. a I

Each access opening of compartments I4 and i5 is provided with an insulated throat or breaker strip structure adapted to prevent con- .duction of heat from the metal exterior walls ll of cabinet it to the metal compartment liners l2 and it. This throat structure comprises a hard strip or strips of molded insulating or molded plastic material 23 around the sides of the access openings of compartments [4 and I5. Each strip 23 has its one edge secured, in any suitable and well-known manner, to the exterior walls ll of cabinet it? and has its other edge secured in any conventional or well-known manner to the edges of liners l2 and 3. The breaker strip Edacross the upper part of compartment !5 is provided with a glass window or with an integrally molded transparent portion 2 3 (see Figs. 3 and 4) for a purpose to be presently described.

The upper compartment i4 is for the storage'or freezing of frozen foods, and is normally maintained at freezing temperatures of from 0." to F. In order to cool compartment ill to this temperature an evaporator 31 in the form of a from evaporator 3!, to cause cooling of the in- I,

terior of compartment is to the temperature range indicated, through conduit 34 (see Fig. 5) whereupon the compressor of unit 32 compresses the refrigerant vapor and discharges same through conduit 35 into condenser 33. compressed refrigerant is cooled and liquefied in condenser 33, in any suitable or well-known manner, from whence the liquified refrigerant is conducted through conduit 36 to the evaporator coil 3i under the control of a suitable expansion valve or restrictor 31.

Starting and stopping operation of the refrigerantcirculating or motor-compressor unit 32 is accomplished by a control switch 4! interposed in electricpower line 42 of lines 42 and 43 leading to the motor. Switch 41 has a closed thermostatic system, charged with a suitable volatile fluid, associated therewith and'comprising bulb 46, conduit 4? and an expansible member such as a bellows ii; employed to transmit movement to switch 4|. Bulb 46 is secured to evaporator 3I'to thus render the thermostatic system responsive to temperaturechanges of the evapor ator'for causing starting and stopping of the compressor of unit 32.

The lower compartment i5 is ordinarily maintained, for example, between and 50-F., for the storage of food products left over from the table, or foods not requiring freezing temperatures for their preservation. In order to cool the interior of compartment HS to the temperature indicated, a closed secondary refrigerant circuit is employed in the present disclosure. Thisclosed secondary circuit comprises a refrigerant evaporating portion or coil 5|, having a plurality of conduit convolutions secured in intimate thermal contact with the outer surfaces of liner l5, and a refrigerant condensing portion or coil 52 secured in intimate thermal contact with thecoil portion 53. of freezing evaporator 3i; This secondary circuit and its function is now well known to those skilled in the art and is fully'described in the reissue patent to J. L. Gibson, No. 21,040, dated April 4, 1939. Instead of employing the closed secondary circuit as here- The in disclosed, the compartments l4 and 15 may be cooled to their different respective temperatures by two primary evaporators connected in series or in parallel with the refrigerant translating device 32 in a manner also well known to those skilled in the art."

Due to the low temperatures maintained in compartments M and I5 and particularly the below-freezing temperature at which the upper foodcompartment is is maintained, a cold zone existsin the vicinity of the door mullion 2|. Such a cold zone is a characteristic of the type of refrigerator disclosed wherein two refrigerated compartments are disposed closely adjacent one another. The cold zone tends to chill the outer wall surface of mullion 2| below the dew point ofthe atmosphereabout the refrigerator cabinet thereby causing condensation of moisture on the exterior surface of mullion 2!. This moisture accumulates on the mullion 2| at a point intermediate. the gasket. seal on the lower side of upper door i'l andthe gasketseal on the upper side of the lower door l3.

It is therefore the purpose of the present invention to prevent such condensation of moisture on themullion 2! by heating the same to a tem perature above the dew point of the exterior atmosphere so that condensation willnot take place thereon, or so that if moisture does condense under extreme conditions it will'soon be evaporated. upon the application of the heat. A modern refrigerator is generally equipped with a door-controlled electric lamp, usually located on the rear wall of the food compartment, for illuminating the interior of the refrigerator when the access dooris opened. I take advantage of. the heat emitted by thislampto supply heat to themullion 2| and this is accomplished by changing the location of the lamp to a. position close to or inside the mullion and somountling it that substantially all of the available heat is transmitted to the mullion. In my preferred construction I employ an elongated incandescent electric lamp 6! mounted in an electric terminal socket 62 located behind the wall of'mullion 2.! adjacent to a transparent portion or window 24 in the breaker strip 23 of the access opening leading to compartment I5. A metal reflector member 63 has an extension 66 welded to or otherwise suitably secured in intimate thermal contact with the inner metal wall surface of mullion 2!. The arcuate shaped portion of reflector 63 surrounds a part of the lamp bulb 61 and is adapted to reflect light from the bulb through the window 24 into the food compartment l5 to illuminate the interior thereof. Lamp 6! may be energized by a conventional door-operated switch which lights the lamp when the door is opened and deenergizes the lamp when the door is closed again. In some cases the heat thus emitted by the lamp may be sufficient to maintain the mullion 2! dry. However, when the door is opened infrequently or when the humidity conditions of the surrounding atmosphere are unfavorable, this may not be sufficient, and I therefore provide a supplemental or alternative switch control means for closing the circuit to the lamp while the refrigerator door is closed to supply additional heat to the mullion. Such supplemental switch means may be operated manually or automatically by any suitable means, as for example, by the periodic opening and closing of the circuit to the electric motor 32.

In the form of the invention-shown in the drawings, I employ a switch having a plurality of contacts in place of the conventional off-on switch operated by opening and closing of door I8. Such a switch comprises a movable arm 66, contact 61, contact 68 and a contact 59 to which the arm 66 is pivotally mounted (see Fig. 5). It is to be understood that any suitable or desirable linkage or like mechanism canbe provided between the arm 66 and door |8 to cause movement of the arm 66 when the door I8 is opened or closed. Contact 68 of this door operated switch is connected by wire 1| direct to power line 42, while contact 61 is connected by wire 12 to power line 42 at a point intermediate the refrigerating system control switch 4| and motor '32. Contact 69 is connected by wire 13 to one terminal of the lamp socket 62, the other terminal ofwhich is connected by wire 14 with power line 43. The electric circuit described causes the lamp 6| to be energized, through switch arm 66 and contact 6%, whenever the cabinet door I8 is opened irrespective of whether or not the motor-compressorv unit 32 is operat-' ing. Lamp 6| will also be energized whenever the circuit to the motor of unit 32 is completed, the lamp circuit in this case being from power line 42 through switch 4|, wire 12, contact Bl, switch arm 66, contact 69, wire 13, lamp 6| and wire 14 to power line 43. Thus the lamp 6| will be intermittently energized, to transfer heat generated thereby to the outer wall portion of mullion 2|, irrespective of whether or not the door l8 of compartment I5 is opened or closed. Ihe

intermittent energizing of lamp 6| causes heat generated thereby to be absorbed by the metal reflector member 63 and due to the contact of reflector 63 with the outer metal wall portion of mullion 2|, as hereinbefore described, the outer surface of the mullion is heated above the dew point of the atmosphere exteriorly of cabinet 16 to thereby prevent condensation of moisture thereon. In Fig. 5 of the drawing, the movable arm 65 of the door-operated switch is shown in its full line positions and in engagement with contact 61. The temperature responsive switch 4| of the refrigerating system is shown with its switch arm in full line or open circuit position. In this position of the switches no current can pass from the power lines 42 and 43 to lamp 6| nor to the motor of unit 32. If new door I8 to food compartment I5 is opened the movable arm 66 of the door-operated switch will be ac tuated to the dotted line position shown in Fig. 5 into engagement with contact 68. When arm 66 engages contact 68 current flows from power line 42 by way of wire I contact 68, switch arm 66, wire 13, lamp bulb 6|, and wire 14 to line 43 to energize the lamp. So long as door l8 re.- mains open, the lamp 6| is energized and heat generated thereby is transferred or conducted to the door mullion 2| by or through the reflector, member 63 and extension 64. Movement of door l8 to closed position again actuates the door operated switch arm 66 into its full-line position in engagement with contact 61 to render the lamp 6| ineffective.

When the temperature of evaporator 3| increases, due to refrigeration demands placed thereon, the volatile fluid in the thermostatic, system expands and causes extension of the bellows 48 to thereby actuate the arm of switch 4| into engagement with its contact as shown in dotted lines in Fig. 5. Engagement of the arm of switch 4| with its contact completes the. electric circuit from power line 42 to power line 43 through the motor of unit 32 to cause operation of the motor and consequently the compressor of the refrigerant translating device to effect a lower temperature of evaporfator 3|. At this same time the lamp BI is energized or rendered effective by current fiowingfrom power line 42, through switch 4|, wire l2, contactfi'l, arm 66 of the door-actuated switch, contact 69, wire 13, lamp bulb 6|, and wire 14 to power line 43. Thus the lamp BI is energized each time the motor of the refrigerating system operates and should door i8 be opened while the motor is operating, movable arm 66 of the door-actuated switch will simply move to the dotted line position shown to complete the alternate electric circuit to the lamp 6| as before described. Thus the lamp will remain energized so long as the motor is running or the door I8 is open.

From the foregoing it will be apparent that I have made an improvement invention by utilizing the lamp employed to illuminate the interior of a food storage compartment of a refrigerator cabinet to perform the double purpose herein described. My improved apparatus eliminates the necessity of providing an extra heaterand the attendant wiring circuit for warming the door mullion, in addition to a food compartment lamp. In my novel arrangement the food storage compartment will be illuminated each time the door affording access thereto is opened while at the same time I insure that the door mullion is sufficiently warmed to prevent condensation of moisture thereon even though the food compartment door may not be opened for long periods of time.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. A refrigerating apparatus comprising in combination, walls forming a cabinet having a food storage compartment therein, said compartment being provided with an access opening, a movable door having a part thereof normally engaging a wall of said cabinet about said access opening for closing same, a refrigerating system comprising means for cooling said compartment and a refrigerant translating device including a refrigerant circulating unit, means for illuminating the interior of said compartment, said illuminating means being disposed in heat exchange relationship with an outer wall portion of said cabinet adjacent said compartment access opening for transferring heat generated thereby to said cabinet outer wall portion, and said illuminating means being normally ineffective and rendered effective automatically by operation of said refrigerant circulating unit.

2. A refrigerating apparatus comp-rising in combination, walls forming a cabinet having a food storage compartment therein, said compartment being provided with an access opening, a movable door having a part thereof normally engaging a wall of said cabinet about said access opening for closing same, a refrigerating system comprising means for cooling said. compartment and a refrigerant translating device including a refrigerant circulating unit, means for illuminating the interior of said compartment, said illuminating means being disposed in heat exchange relationship with an outer wall portion of said cabinet adjacent said compartment access opening for transferring heat generated thereby to said cabinetouter wall portion, and said il1ucomp-rising in combination, a plurality of walls forming a cabinet provided with a first food storage compartment and a second food storage compartment insulated from one another and each having an access opening with a mullion therebetween, a movable door for each of said compartment ac cess openings, each of said doors having a part thereof normally engaging said mullion and other portions of an outer wall of said cabinet about said access openings for closing same, a refrigerating system comprising means for cooling compartments and a refrigerant translating device including a refrigerant circulating unit, means for illuminating the interior of one of said compartments, said illuminating means being disposed in heat exchange relationship with an outer wall portion'of said muilion for transferring heat generated thereby to said mullicn outer wall portion, and said illuminating being normally ineffective and rendered effective automatically by operation of said refrigerant circulating unit.

4., A refrigerating apparatus comprising in combination, a plurality of walls forming a cabinet provided with a first food storage compart ment and a second food storage compartment insulated from one another and each having an access opening with a mullion therebetween, a movable door for each of said compartment access openings, each of said doors having a part thereof normally engaging said mullion and other portions of an outer wall of said cabinet about said access openings for closing same, a refrigerating system comprising means for cooling said compartments and a refrigerant translating device including a refrigerant circulating unit,

' means for illuminating the interior of one of said compartments, said illuminating means being dioposed in heat exchange relationship with an outter wall portion of said mullion for transferring heat generated thereby to said mullion outer wall portion, and said illuminating means being normally ineffective and rendered effective automatically by movement of the door of said one compartment and/or by operation of said refrigerant circulating unit. 7

5. A refrigerating apparatus comprising in combination, a plurality of walls forming a cabinet provided with an upper food storage compartment and a lower food storage compartment insulated from one another and each having an access opening with a mullion therebetween, a movable door for each of said compartment access openings, each of said doors having a part thereof normally engaging said mullion and other portions of an outer wall of said cabinet about said access openings for closing same, a refrigerating system comprising means for cooling said compartments and a refrigerant translating device including a refrigerant circulating unit, an insulating breaker strip extending around the access opening of said lower compartment and disposed between the liner thereof and the cabinet outer wall, that part of said breaker strip along the upper wall of said lower compartment. including a transparent portion, an in candescent electric lamp located within the insulated wall between said compartments and adapted to direct rays emitted therefrom through said transparent portion of said breaker strip into said lower compartment for illuminating the interior thereof, said-lamp being disposed in heat exchange relationship with anouter wall portion of said mullion for transferring heat generated thereby to said mullion outer wall portion, and said lamp being normally ineffective and rendered effective automatically by movement of said door of said lower compartment and/or by operation of said refrigerant circulating unit.

6. A refrigerating apparatus comprising in combination, a plurality of walls forming a cabinet provided with an upper food storage compartment and a lower food storage compartment insulated from one another and each having an access opening with a mullion therebetween, a movable door for each of said compartment access openings, each of, said doors having a part thereof normally engaging said mullion and other portions of an outer wall of said cabinet about said access openings for closing same, a refrigerating system comprising means for cooling said compartments and a refrigerant translating device including a refrigerant circulating unit, an insulating breaker strip extending around the access opening of said lower compartment and disposed between the liner thereof and the cabinet outer wall, that part of said breaker strip along the upper wall of said lower compartment including a transparent portion, an incandescent electric lamp located within the insulated wall between said. 0011" artments above said transparent portion of said breaker strip, a metallic memher around a portion of said lamp for directing rays emitted therefrom through said transparent portion of said breaker strip into said lower compartment to illuminate the interior thereof and for absorbing heat generated by said lamp, said metallic member having a part thereof in intimate thermal contact with an outer wall portion of said mullion for transferring heat absorbed thereby from said lamp to said mullion outer wall portion, and said lamp being normally ineffective and rendered efiective automatically by movement of the door of said lower compartment and/or by operation of said refrigerant circulating unit.

7. A refrigerating apparatus comprising in combination, a plurality of walls forming a cabinet provided with a first food storage compartment and a second food storage compartment adjacent thereto and insulated from one another, each of said compartments having an access opening with a mullion therebetween, a movable door for each of said compartments and normally closing the access opening thereof, a refrigerating system associated with said cabinet, said system comprising means for cooling one of said compartments below 32 F., means for cooling the other of said compartments above 32 F. and a refrigerant translating device including a refrigerant circulating unit connected in closed circuit relation with at least one of said cooling means, means for illuminating the interior of one of said compartments, said illuminating means being disposed in heat exchange relationship with an outer wall portion of said mullion for transferring heat generated thereby to said mullion outer wall portion, and said illuminating means being normally ineffectice and rendered effectiveautomatically by operation of said refrigerant circulating unit.

8. A refrigerating apparatus comprising in combination, a plurality of walls forming a cabinet provided with a first food storage compartment and a second food storage compartment adjacent thereto and insulated from one another, each, of said compartments having an access opening with a mullion therebetween, a movable door for each of said compartments and normally closing the access opening thereof, a refrigerating system associated with said cabinet, said system comprising means for cooling one of said compartments below 32 F., means for cooling the other of said compartments above 32 F. and a refrigerant translating device including a refrigerant circulating unit connected in closed circuit relation with at least one of said cooling means, means for illuminating the interior of one of said compartments, said illuminating means being disposed in heat exchange relationship with an outer wall portion of said mullion for transferring heat generated thereby to said mullion outer wall portion, and said illuminat- 10 ing means being normally ineffective and rendered efiective automatically by movement of the door of one of said compartments and/or by operation of said refrigerant circulating unit.

JOHN R. FEHR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,852,707 Hoffman Apr. 5, 1932 2,135,091 Newill Nov. 1, 1938 2,443,342 Colvin June 15, 1948 2,491,105 Gaugler Dec. 13, 1949 

